The Y2K crisis that never happened:
PART 1

There were some dates on which special problems were expected to occur. A technology consulting firm, the Gartner Group, ₉ predicted that only 8% of the Y2K problems will actually happen on 2000-JAN-1. They further estimated that 58% of the potential millennium bugs would have been activated on dates prior to 1999-MAR. Some critical dates were/are:

	Prior to 1999: Credit card renewals prior to the year 2000 were prone to failure. This is because the cards' expiry dates were been in the year 2000 and beyond. This problem was presumably solved in time; we have not heard of any banks going out of business or not being able to issue credit cards to their customers.
	1999-JAN-01: Some old computer programs reserved the number "99" for some special use - for example as an error code. As expected, this caused problems in a number of computer programs in early 1999. However, they were apparently minor as we could find only three significant failures reported in the media: Immigration officers at three Swedish airports had failures in computer programs that issue immediate, temporary passports to last-minute or forgetful travelers. Technicians were able to fix the problem easily in a few hours. Taxi meters in Singapore allegedly failed for two hours in the middle of New Years Day. Two computer-operated medical devices partially failed. A defibrillator manufactured by Hewlett-Packard and a patient monitor sold by Invito Research Inc failed to display the correct date and time.  Their other functions were unaffected.
	1999-FEB-4 & 5: Many airline reservation systems can handle flights up to 330 or 331 days in advance. On these dates in 1999-FEB, people were able to make reservations for 2000-JAN-01 flights. The over 100,000 travel agencies worldwide book about 80% of their reservations through only a handful of computer reservation systems (CRS): Sabre, Galileo, Amadeus, WorldSpan are the largest. These systems passed the critical days relatively uneventfully. The small percentage of travel agencies which were not Y2K compliant had their reservation requests for the year 2000 rejected.
	1999-MAR-01, JUL-01, OCT-01...: These are commonly used beginnings of fiscal years of many businesses. Since their fiscal year ended in the year 2000, there was some fear that program failures may occur. 46 state governments in the U.S. started fiscal years on JUL-1 without major problems. No problems were reported.
	1999-APR-9: This was the 99th day of 1999. Unfortunately, 99 is sometimes used inside computer programs as an "end of file" (EOF) marker. This date was chosen by the North American Electric Reliability Council (NERC) to test the preparedness of all of the electrical utilities in the U.S. and Canada. Again, no failures seemed to have surfaced.
	1999-SEP-09: This day may be expressed as 9/9/99 or 99/9/9. In shorthand, a computer might represent it as 9999. This is another potential EOF (end of file) marker. NERC choose that date for its second test of the electrical power grid. Again, the day seems to have passed without any noticeable problems.
	2000-JAN-01: This was seen as the "biggie:" the first date with a year ending in "00." Some computer programs were expected to interpret this as the year 1900. Others might sense it as an error code. Others might give unpredictable results. Fortunately, this day fell on a Saturday, so many computer programmers had two days to solve the problems before the work week began on Monday. The downside is that many companies had to pay overtime to their employees to stand by in case problems develop. It is obvious from media reports that few problems were encountered.
	2000-JAN-03: This is the first working day in the New Year for some companies; JAN-04 was for others. Only then did some of the Y2K problems become apparent. They seem to have been quickly solved.
	2000-FEB-28: A few programmers believe that century years are not leap years. Thus, they wrote programs assuming that the year 2000 was not a leap year. But in the Gregorian calendar system, years which are evenly divisible by 400 are all leap years; this includes the year 1600, 2000, 2400, etc. Again, this produced minimal problems.
	2000-OCT-10: This is the first date in this year that requires 8 characters for a full notation (as in 2000 10 10) or 6 characters for an abbreviated notation (as in 00 10 10).
	2001-JAN-01: Since the first year in the Common Era (CE) was the year 1, then the first year of the second century CE was 101 CE. And the first year of the third millennium or 21st century will be 2001. Thus, 2001-JAN-01 will be the first day of the next millennium. Of course, many will have already celebrated the event one year earlier. A survey of readers to the Countdown 2000 web site in 1999-JAN-09 indicated that 36% regarded 2000-JAN-1 to be the beginning of the new millennium; 45% picked 2001-JAN-1; 20% don't care. 10 It might be possible for a computer program to contain programming that would bomb out on this day. However, it is unlikely.
	2038-JAN-19: Many computer program written in C++ will fail on this date at 3:14:07 GMT. Those programs that use the "signed 32 bit long integer" time keeping functions of C/C++ keep time by computing the number of seconds since 1970-JAN-1 at 00:00 GMT. In 2038-JAN-19, they will reach 2,147,483,647 which is the largest number that the program can store. Later dates/times will be expressed in negative integers which are reserved for error codes. The results are unpredictable.
	Other dates: Many specialty programs have their own system of time keeping. They typically measure the number of seconds, or milliseconds or deciseconds after a specific date and time. Eventually, these systems will reach their limit in the same way as the C++ programs will. Each system has its own unique termination date.